`timescale 1ns/1ps

module tb_uart;

    reg clk = 0;
    reg tx_enable = 0;
    reg tx_ready;
    reg [7:0] data_in = 8'h00;
    reg [7:0] data_out;

    reg rx_received;
    wire rx_enable = 1'b1;

    wire pin;

    always #18.5 clk = ~clk;

    localparam CLK_FREQ = 27_000_000;
    localparam BAUD_RATE = 115_200;

    uart_rx #(
        .CLK_FREQ(CLK_FREQ),
        .BAUD_RATE(BAUD_RATE)
    ) rx_instance (
        .clk(clk),
        .rx_pin(pin),
        .rx_data(data_out),
        .rx_received(rx_received),
        .rx_enable(rx_enable)
    );

    uart_tx #(
        .CLK_FREQ(CLK_FREQ),
        .BAUD_RATE(BAUD_RATE)
    )tx_instance (
        .clk(clk),
        .tx_enable(tx_enable),
        .tx_ready(tx_ready),
        .data(data_in),
        .tx(pin),
        .rst_p(1'b0)
    );

    initial begin
        $dumpfile("runs/uart.vcd");
        $dumpvars(0, tb_uart);

        $display("======== Start UART LOOPBACK test =========");

        #100;

        data_in <= 8'd234;   // 234
        tx_enable <= 1;
        wait(tx_ready == 1'b0); 
        tx_enable <= 0; 

        // Attendre
        wait (rx_received == 1'b1); // Attendre que le signal de reception soit actif

        $display("Data received: %d", data_out); // Afficher la valeur recu
        $display("Data expected: %d", data_in); // Afficher la valeur envoyee

        #1000;

        wait(tx_ready == 1'b1); // Attendre que le signal de reception soit actif

        data_in <= 8'd202;   // 202
        tx_enable <= 1;
        wait(tx_ready == 1'b0); 
        tx_enable <= 0; 

        // Attendre
        wait (rx_received == 1'b1); // Attendre que le signal de reception soit actif

        $display("Data received: %d", data_out); // Afficher la valeur recu
        $display("Data expected: %d", data_in); // Afficher la valeur envoyee

        $display("======== END UART TX test =========");

        #1000;
        $stop;
    end

endmodule